"In our increasingly busy lives, we're just under a lot of stress. And I think, when that stress is left unchecked for a period of time, it can start to eat away at our psychological and physical well-being," said study co-author Dr. Randy Cohen, a cardiologist at Mt. Sinai St. Luke's-Roosevelt Hospital Center in New York City.

Results of his research show that vital exhaustion is on par with other proven psychological risk factors for heart disease, including depression and anxiety, Cohen added.

Vital exhaustion goes far beyond mere fatigue, he said. It occurs when unrelenting stress starts to have an effect on a person's ability to recover from fatigue.

"It's this ongoing sense of fatigue, lack of energy that prevails even after getting a good night's sleep, even when you're not suffering from any illness," he said. As a result of this gnawing fatigue, people become irritable and develop feelings of demoralization.

Researchers examined the relationship between vital exhaustion and first-time heart disease by combining the results of 11 studies that included more than 60,000 people without heart disease. The studies had an average six and half years of follow-up.

Even after adjusting for other risk factors, vital exhaustion continued to increase a healthy person's risk of heart disease by about a third, the researchers concluded.

Findings from the study were scheduled to be presented Monday at the annual meeting of the American Heart Association in Chicago. Findings presented at meetings are considered preliminary until they are published in a peer-reviewed journal.

These results add to an already large body of evidence showing that stress and fatigue can affect a person's heart health, said Dr. Richard Becker, chief of the Division of Cardiovascular Health and Disease and director of the Heart, Lung and Vascular Institute at the University of Cincinnati.

"Because the cardiology community has been aware for some time that there were some personality considerations that contribute to heart disease, I don't see this as something that is brand new," Becker said.

Stress and fatigue can affect heart health in two ways, Cohen and Becker said.

Stressed-out exhaustion can affect levels of stress hormones like adrenaline and serotonin in the body. These hormones can interfere with a person's immune system and create inflammation in the body, the experts explained.

"You can certainly tell a very good sound biological story that links with the psychological contributors to heart disease. They do fit together," Becker said.

People under extreme stress and fatigue also tend to indulge in behaviors that are bad for heart health, Cohen noted. They might smoke or eat unhealthy foods as a way of dealing with stress, for example.

Folks who think they are suffering from vital exhaustion should take steps to reduce stress in their lives, Cohen said. How? Try getting more exercise, eating a healthy diet, and engaging in stress reduction techniques like yoga or meditation, he suggested.

Primary care physicians also can play a role, by including stress and fatigue in the other symptoms they look for when conducting regular exams of patients, Cohen and Becker said.

"Perhaps with their yearly physical examination, clinicians would be looking for some of these features," Becker said. "Clinicians tend to focus on physical risk factors like cholesterol and high blood pressure. In addition to those very important things, there are other considerations that must be in place to really address a person fully."